Primary signal detection over Rayleigh fading channel for cognitive radio

This paper studies the primary user (PU) signal detection methods over Rayleigh fading channel in cognitive radio system. We propose a double threshold detection with channel selective. In this method, cognitive user receives signals by selecting the maximum SNR channel, so it can effectively detect the primary user (PU) signal in Rayleigh fading environment. And the influence on detection performance is also analyzed when the distance changes between the primary user and cognitive users. Simulation results show that, when the false alarm probability is constant, the detection probability is larger and misdetection probability is smaller as the distance increases between primary user and cognitive user. The proposed method is superior to the conventional energy detection method and double threshold detection method.